<template> 
  <Demo @hello="showHello" msg='凌宸你好啊' school="ncu">
    <template v-slot:lingchen>
      <span>HelloWorld</span>
    </template>
  </Demo>
</template>

<script>  
import Demo from './components/Demo'
export default {
  name: 'App',   
  components:{Demo},
  setup(props , context) {
    function showHello(value){
      alert(`触发了 hello 事件，我收到的参数为：${value}`)
    }
    return {
      showHello
    }
  }
}
</script>

